Tars of various derivations, such as coal tar, wood tar, and gas tar, have numerous uses in, for example, roofings, coverings, paints, the impregnation and preservation of wood, adhesives and binders, road coverings and compositions, and asphalt materials. In addition, tar is a source of chemicals like phenol, benzene and toluene.
Among the most common uses of tar is for sealing the roof so that the interior of the dwelling, be it a residential or commercial structure, remains impervious to the infiltration and seepage of water or moisture. The tar is used in conjunction with roof sheathing, roofing paper and felt and shingles to completely seal the roof and maintain the integrity of the interior dwelling rooms and spaces.
However, over the passage of time, and as part of the normal break down and deterioration experienced in materials and structures, roofs develops fissures, cracks and leaks that require maintenance and repair; and part of the roof maintenance and repair involves the selective re-application of tar to those parts or portions of the roof undergoing break down and deterioration. Oftentimes the leaks and cracks are of a minor dimension but still sufficient to impair the integrity of the roof, and thus require only a small and selective application of tar thereon. While a building or roofing contractor is not needed in such instances, some means or structure is still needed to melt and heat the tar and/or asphalt for application to the surface or area requiring the maintenance and repair.
Thus, the prior art discloses several tar and asphalt melting kettles such as the Schrader patent (U.S. Pat. No. 3,995,616). Schrader discloses a towable asphalt kettle that includes a heating and melting chamber and a closure disposed over the chamber having chute portions terminating with openings for loading tar chunks into the chamber. Each chute portion has a hinged door for closing off the chute portion from the closure to minimize the escape of gas or asphalt and to seal the closure from the external environment upon the occurrence of a pressure differential.
The Lehman et al. patent (U.S. Pat. No. 4,033,328) discloses a towable tar-melting kettle that includes a vat in which an immersion tube unit is placed, and the immersion tube unit contains the burners and conduit used to heat the chunks of tar. A double rotating cylinder registers with the immersion tube unit that permits chunks of tar to be placed into the rotating cylinder for deposition into the vat without exposing the melting tar to the environment and preventing the tar from splashing outside of the vat.
Despite the ingenuity of the above devices, they are large, unwieldy and generally unnecessary for the repairs and maintenance required of typical home and office owners.